Nano Reef Keepers FAQ

ORIGINAL V.001 FAQ BY This email address is being protected from spambots. You need JavaScript enabled to view it.

2nd EDITION 12/25/97 BY CHARLES DEVITO, This email address is being protected from spambots. You need JavaScript enabled to view it.

3rd EDITION 3/18/98 BY CHARLES DEVITO, This email address is being protected from spambots. You need JavaScript enabled to view it.

NANO REEFKEEPERS FAQ Version 3.00

Notes on this edition: this is a total revision of the v1.02 FAQ, written expressly for the benefit of the Reefkeeper's mailing list. Attempts to contact the author of the original v.01 FAQ have continued to fail. Accordingly, I have now decided to alter his original text rather then merely add my own comments after his remarks. Many sections of this document have undergone complete re-writes since v1.02 (lighting, skimming, inhabitants,etc) and every section has undergone at least significant revision. Permission is granted to copy/duplicate/disseminate this document for all non-commercial purposes providing the entire document is left intact.

This FAQ is organized into the following sections:

[1.0] What is a nano-reef?

[2.0] Why would I want to keep one?

[3.0] I am new to reefkeeping. Is this a good low-cost way to get my feet wet?

[4.0] Tank selection.

[5.0] Lighting.

[6.0] Heat/cooling.

[7.0] Circulation.

[8.0] Use of a sump.

[9.0] Water Quality / nutrient additions.

[10.0] Protein skimmers.

[11.0] Live Rock & live sand.

[12.0] Tank Cycling

[13.0] Livestock

[14.0] Costs

[15.0] Changes planned for the next revision

[1.0] What is a nano-reef?

A nano-reef is any reef tank of less than twenty gallons. This is somewhat of an arbitrary distinction - some would classify any tank under 55 gallons "nano" - but I have chosen to draw the line at less than 20 gallons primarily because that is the point where many of the commonly accepted formulas and practices for mini- and micro-reefkeeping begin to break down, calling for alternative means and methods.

Please note that I use the terms Micro and Nano pretty much interchangeably. Any distinction between the two is inconsequential.

[2.0] Why would I want to keep one?

[A] Low cost. You can easily get away clean for less than $200

[B] They fit in a small space.

[C] Nanos are easy to maintain.

[D] Portability. You can take it home in the summer, and to work in the winter!

[E] They provide a new level of challenge to the experienced reefkeeper, without the accompanying ever-more-costly and time consuming negatives associated with keeping larger tanks.

[F] Nanos are cool! Nano-reefs can take on a very zen-garden like quality - every little placement and consideration counts.

[3.0] I am new to reefkeeping. Is this a good low-cost way to get my feet wet?

It can be, providing you do your research before hand and you are willing to absolutely perform the required maintenance involved. Despite the fact that nano-reefs are low cost and low maintenance, they arestill considered experimental because there are still a few areas of their keeping that remain nothing more then "best guesses". Small volumes of water also provide very little room for error, either in terms of maintaining water quality or stable temperatures. Oxygen depletion and deadly detritus buildup are very real dangers innano-reefs. Selecting the right livestock of the appropriate size and/or quantity is also a big challenge - and unless you are already familiar with the species you are adding, it is very easy to make mistakes. Finally, there are definite limitations as to what you can have in the tank - particularly in the area of fish - and most beginners want to leave their options open.

While a nano should not be the preferred way to get into reef keeping, it is a viable method. My 16 year old sister, who has never kept so much as a freshwater goldfish, has been successfully maintaining a 5 gallonnano for some time now. Jumping into reefkeeping with a nano is not impossible, nor even unduly difficult. It is, however, unforgiving of mistakes.

[4.0] Tank selection.

If you are planning on using a standard glass tank, it is a good idea to keep in mind that many smaller tanks are of poor quality. In particular, there is usually no caulking around the plastic ringing the top of the tank. This can be problematic, since even small airstones or bubblers can produce a 1/2+" water bulge on the surface - if your tank isn't sealed, you may well have to settle for having the waterline 2+" from the top, which is unsightly. You may want to caulk around the inside rim of the tank using aquarium-safe silicone sealant (of course, wait at least 24 hours for the sealant to cure before adding water).

Small acrylic tanks with internal wet/dry filtration hidden in compartments in the back are often seen for sale at pet shops. While these tanks can be used, they really aren't the best choice. Most likelyyou will wish to disable the wet/dry in any case, and while the empty media compartments make a good place to hide a heater and a skimmer you still loose an awful lot of tank volume using these tanks. Additionally, they can be quite expensive.

[5.0] Lighting.

[A] Amount.Lighting a Nano or Micro reef is something of a complex issue. While many people feel that they can keep a Nano with the traditional 3-7 watts per gallon of light, others feel that regardless of the watts pergallon ration 30 watts is still only 30 watts. I know of several people who are successfully keeping nanos withlighting on either side of this argument. The original author of the NANO FAQ claims to have heard of someone successfully keeping acropora species in a 2.5 gallon tank lit with only 18 watts of Power Compactlighting. DC Potts (creator of Project:PICO Reef) maintains that his tridacna clams were not happy until they received approximately 50 watts of lighting (which brought him up to around 17 watts pergallon on the size tank he was maintaining). These contradictory statements make it difficult to determine just what the lighting requirements of a nano actually are.

I've done some experimenting which has led me to the opinion that the traditional wattage per gallon rule is, indeed, insufficient on a nano. The first few nanos I set up used the low-end of the lighting spectrum, usually around 3 watts per gallon. All of these setups used Power Compacts. While the inhabitants (species with low to medium light requirements) did okay, none were really thriving. Growth rates were nonexistant. While I feel that the inhabitants of these tanks were in no danger of death through light starvation, they were neverthelesscertainly not as healthy as they could be.

About six months ago I removed the 45 watts of Power Compact lighting I had on a 15 gallon tank and replaced them with a 175 watt 10,000K Metal Halide bulb. From 3 watts per gallon the tank went up to just under 12watts per gallon. The results were spectacularly positive. I have light loving corals (no SPS, though) that are thriving and growing, as well as low light corals (mushrooms) which have also visibly improved with theadditional lighting intensity. I mention the mushrooms specifically because they are known to be low-light animals; for all that, they have not suffered from the high intensity lighting in the least. None of the animals in the tank were scorched or shocked from the additional lighting; a two week period of gradual acclimation was used to prevent light shock or bleaching.

What it comes down to is that while you can have a successful coral tank using the standard 3-7 watts per gallon rule, your tank will be that much healthier if you provide larger quantities of light.

EXPERIMENTAL: Recent conversations with Jimmy Chen, Ron Shimek and others concerning Craig Bingman’s suggestion of scrapping the old “watts-per-gallon” rule in favor of “watts-per-square-foot-of-tank-surface-area” look very promising. Initial comparisons seem to definitely support watts/ft2 as a more accurate measurement of a tank’s requirements. It has been suggested that the target number one should shoot for on a 24” deep tank is 100w/ft2; my own best guess is that anywhere from 55-75w/ft2 would be perfect on a tank 12” deep or less. You may wish to bear this in mind when figuring out how much light to use on your tanks.

[B] Flourescents.Let me say right off that I don't like flourescents, be they NO, HO or VHO. Quite simply, they are the least intense form of lighting on a watt-by-watt basis. At the same time, especially on a small tank, they can be much more costly to operate then any of your other options.

If you wish to use flourescents on a nano, you are advised to use VHO bulbs. This will mean the purchase of a good ballast, and your setup cost will probably be as high as if you used Power Compacts or Metal Halides. You could use NO bulbs, but you would need quite a lot of them; an absolute minimum of two or three 15 watt bulbs would be needed on a 10 gallon tank, for example, and four or five would be better.

You will need to use a mix of actinic "blue" bulbs and daylight "white" bulbs. It's important to buy bulbs intended for use with reef tanks, as only with these will you be sure you are providing the correct spectrumsof light neccessary for the health of your corals. Yes, they cost a few dollars more, but they are a requirement. NO output bulbs need be replaced at least once a year; HO and VHO bulbs should be replaced every six months. Since HO and VHO bulbs are not cheap, and since you'll be using a few of them at the same time, bulb replacement can be costly.

[C] Power Compacts.In my opinion, Power Compacts (PCs) are a big step up from regular flourescents on any tank. On small tanks these bulbs really come into their own, however. PCs are significantly brighter and smaller then normal flourescents of the same wattages. They are available in 5700K "white", 7100K "blue" and "red" (for night-time viewing) spectrums. Common wattages that are useful with a nano tank include the 9 watt, 27 watt and 28 watt bulbs. The 27 watt is a quad bulb (twice the standard PC bulb width), which should be taken into account when designing a canopy with them in mind.

Three small fixtures are commonly available that are perfectly designedfor use with nano reefs. The first of these is the MiniMite from Coralife, which retails for around $75. This fixture uses 1 9w white bulb and 1 9w blue bulb, mounted in a plastic enclosure. It's best used for really small tanks (such as a 2.5 gallon). I own one and have been reasonably happy with it, but must say that I've found it to be puttogether poorly. Mine is held together with a couple of rubber bands.

Custom SeaLights offers a fixture with a 27w quad "white" bulb and a 9w "blue" bulb, for double the total wattage of the MiniMite. Surprisingly, it retails for about the same amount ($75) as the MiniMite. I have notused one so I cannot comment on their construction, but I have heard very good things about them.

Finally, a number of different outfits offer a 15" fixture containing a 28w "white" and a 28w "blue" bulb, for a total of 56 watts. This size is perfect for a 10 gallon aquarium, and may fit on some 5 gallons as well (depending on specific measurements). It's available as both a retrofit kit (for around $130) and a canopy (for around $170). Many people speak very positively about these, as well.

The jury is still out over just how often PC bulbs need to be replaced, although it appears that at most they need to be changed once a year. Some individuals report no loss of light or fall off in spectrum for up to 18 months, however. PC bulb costs are slightly higher then VHO bulb costs, but since you need to replace them far less often they are much more economical.

[D] Metal Halides.I think Metal Halides (MH) have a place in the world of Micro and Nano reefs. I am, however, seemingly alone in this opinion. When I expressed my plan to put a 175w MH fixture on my 15 gallon tank I was met with stunned incredulity. I was told the fixture would generate too much heat for such a small tank (wether I used a ventilation fan or not), and that it would be too much light for ANY coral.

Well, guess what? I have less of a temperature problem with my MH then I did with my Power Compacts, and without a ventilation fan. As far as the light scorching my corals, my mushrooms (as mentioned above) arethriving.

The heat issue shouldn't be brushed off. MH bulbs do generate a lot of heat in a small area. The fixture on my 15 gallon is open, however -- no canopy. In addition, the bulb is mounted 11" above the surface of the water. The tank's temperature is fine like this, even in the summer (I live in L.A.). If I needed to bring it down a degree or two, I could add small muffin fans (available cheaply at Radio Shack) to the fixture.

Scorching corals is also not a laughing matter. However, it is easily avoided. Whenever corals are being moved from one intensity of light to another, they need an acclimation period to adjust. This is easily accomplished by either running the light for only a few hours a day and gradually increasing the photoperiod, or by raising the fixture so the bulb is further away, thus attenuating the light. Slowly it can be lowered to it's regular height. New specimens can be placed in shady areas of an established tank, then gradually moved out and into the open.

I'd say a single 175 watt metal halide is good for a 15 or 20 gallon tank. A 100 or 150 watt metal halide would work for a 10 gallon, and a 70 watt fixture for a 5 gallon. I have not had any direct experience with the new 70 watt MH fixtures and bulbs; anyone who has, please email me. I very much want to hear your experiences.

Metal Halides provide the absolute brightest intensity of light available currently for reef tanks. They blow the competition away, hands down. The only people I usually hear make negative comments about them are those who have already spent a large sum of money on VHO systems and their upkeep.

The bulb of choice for nano and micro keepers should be either the 10000K, 14000K or 20000K bulbs. These bulbs have a lot of blue in their output, obviating the need for supplemental flourescent actinic lighting. Since there's limited room above a small tank, being able to do away with additional bulbs is very useful indeed.

Pendant-style fixtures are a good choice, because they leave the tank top 'open', allowing for significant ventilation and heat exchange. They also can be raised and lowered easily, which is another plus. Expect tospend $200-$300 for a 175 watt pendant, depending on the bulb type you get.

Metal Halide bulbs are expensive, and need to be changed yearly. The 4300K bulbs are not suitable for use in reef tanks, which is a shame as they cost around $20. The 5500K are acceptable but not great, and sell for around $50. The 10000K, 14000K and 20000K bulbs all cost around $100 each. This sounds like a lot, but you're only replacing one bulb a year (on a nano or micro); this actually makes it cheaper then most VHOsystems (again, on a nano or micro).

[6.0] Heat/cooling.

Heating a Nano is a little counter-intuitive. Small heaters simply do not do a good job of adjusting to the wide temperature fluctuations common in a small body of water. By using a heater 2-3 times more powerful then you think you’ll need you’ll find your tank’s temperature staying much more stable then by using a heater of the conventionally recommended size. In a Nano, stable temperature control is very important; temperature shifts in small tanks can be quite large and very frequent in a small tank otherwise.

Cooling a nano-reef is an even more difficult problem. Most simply end up keeping it in an air-conditioned room. Evaporative cooling with fans is probably not the best idea, as the amount of evaporation this can cause can (in a small tank) produce wide shifts in specific gravity which the tank’s inhabitants will not appreciate.

[7.0] Circulation.

Like with larger reefs, adequate water circulation is absolutley essential - probably more so when you consider the reduced surface area and that you may have temperature spikes, which will result in lower levels of dissolved oxygen.

A suprisingly effective solution is to use an open-ended bubbler (a piece of submerged airline tubing works OK, but a rigid tube may be easier to keep in place). In small spaces, bubblers can provide really excellent water circulation. In a 2.5g, one bubbler provides enough current to keep water circulating quite nicely in all sections of the tank. Obviously, the larger the tank, the more bubblers you will want to add.

Use of airstones can be problematic. They are quieter than bubblers, but produce a fine salt spray that will either quickly coat your cover glass/lighting, or encrust evrything around the tank in a fine layer of salt. I have also noticed that "salt creep" (the accumulation of salt deposits around the top and down the sides of the tank) is pronounced.

Small powerheads with adjustable flow are currently available. Some of these units can be set as low as 24 gph, which allows their inclusion in tanks as small as 2.5 gallons. Powerheads can eat up a porportionately large amount of in-tank real-estate in a nano, but otherwise there’s no reason not to use them.

[8.0] Use of a sump.

While there is no doubt that using a sump would greatly aid in the temperature and nutrient buffering capabilites of a nano, few people make use of one.This is probably because of several considerations: it adds to the complexity of the system, it takes up considerably more space, and not least, most of the nano's I've heard of have no stand, so there is no convenient place to put a sump.

Julian Sprung (to give an example) has a 15 gallon Nano -- plumbed to a 60 gallon sump. While this may seem silly at first glance, it actually makes sense. The 60 gallon sump makes the 15 a very stable environment that can be jam packed with life, but lighting the 15 would cost a heck of a lot less then lighting a 60 gallon.

[9.0] Water Quality / nutrient additions.

The well-worn adage "the solution to pollution is dilution" is especially valid in nano-reefs. Because we are dealing with a small volume of water, it is a relatively painless task to perform major partial water changes on a regular basis.

I typically do a 25+% water change every week or two (although I sheepishly admit to forgetting for up to a month), a task that takes maybe ten minutes. This is primarily what makes keeping a nano such alow-maintenance proposition.

Frequent water changes allow you to basically ignore several factors that concern reef keepers.The first of these is trace element depletion. The only two supplements that you should ever have to even consider using are calcium (depending entirely on what animals you keep) and possibly iodine (again, depending entirely upon what animals you keep). Frequent regular partial water changes will more then make up for all other nutrients removed from the system, either by skimming or uptake by the inhabitants. Even calciumand iodine may well be unneccessary, but every tank is different in this regard.

If you do need to dose calcium, the recommended method for a tank without a sump is one of the two part additives on the market (calcium + buffer).

[10.0] Protein skimmers.

I feel a skimmer should be a part of a nano reef, even though the regular water changes outlined above will obviate most of the need for skimming. I personally only run my skimmer for a few hours a week, but it most certainly does pull out gunk when I do so. You can live without a skimmer, but especially if you miss doing a scheduled water change from time to time you'll be glad to have one.

The CPR Bakpak is an excellent skimmer -- but it won't fit on most nanos, as it's too tall. The SeaClone skimmer has mixed reviews, but is fairly reasonably priced and will fit on a 12" tall aquarium (such as a tall 5 gallon, or a standard 10 gallon).

There remain (at this time) two other alternatives. The first is an internal counter current skimmer. These do eat up a lot of space on a small tank, but you can purchase an outside power filter, remove it's media and place the skimmer inside it's body. This will keep the skimmer out of the tank and provide some circulation and aeration as well.

The second choice is the very controversial Skilter. It's detractors call it a worthless, useless device, while those who like it tend to be nearly religious about it.Personally, I find that contrary to what you will hear, it does skim -- it just doesn't skim very well. The smaller model (the Skilter 250) is a viable choice on a 5 gallon tank, whereasthe larger (the Skilter 400) can be used on 10 or 15 gallon tanks. If you don't mind messing with air stone settings, I strongly recommend the CC Skimmer/power filter combination listed above over using a Skilter.

[11.0] Live Rock & live sand.

There are two rules of thumb to use when adding the initial quantity of live rock to the tank:

[1] use the highest quality live rock you can get your hands on, and [2] you probably need less than you think.

The use of exceptionally high quality rock is a matter of taste, but to many nano-keepers, maximum bio-diversity and beauty are especially important in a small space. Besides, you are only buying a couple or few pounds, so it's not going to break your bank account.

You will probably be able to initially get away with less rock per gallon than you would normally add to a larger tank simply because many of the invertebrates you will be adding later will come with their own chunk of rock.

Live sand is entirely optional, of course, but again, since it is cheap in small quantities and may add denitrifying capability, bio-diversity, and good-looks to the tank, most people seem to include it. The only consideration in adding live sand is selection of sand stirrers, which is somewhat limited. Sea Cucumbers should never be included in a Nano.Blue legged hermit crabs work in tanks of all sizes, and polycheates (worms) in the sand also serve an important role. However, I have found that manual sand stirring may be necessary fromtime-to-time.

[12.0] Tank Cycling

Most of the nano-keepers I have conversed with have sought to minimize bacterial cycling. The best way to do this is to pilfer your live rock and sand, plus some water, if possible, from an existing well-established reef.

Most reef shops that maintain quality tanks will be happy to sell you small quantites. You will want to minimize exposure of your live rock and sand to air during transportation and tank setup - it's pretty easy to keep a few pounds of rock and sand submerged during transport. Again, it's probably best not to skimp on quality, since a major dollar investment isn't required.

[13.0] Livestock

[13.1] Stony Corals.

It is possible to keep many types of stony corals in a nano, but there are several considerations in selection that will determine your success. First, you obviously want small colonies - a 12" elegance won't cut it. Second, one has to be especially careful of contact problems in a small tank. Stony corals that have been successfully kept include:

* Acropora - small cuttings of about an inch.

* Bubble Coral (Plerogyra sinuosa).

* Favites

* Closed Brain Coral

* Fire Coral -(OK, its not a stony, but it acts like one)

*Hammer Coral

*Torch Coral

*Organ Pipe Coral (again, not a true stony, but acts like one)

*Elegance Coral

I have found that sweeper tentacles are not as much of a problem as might be imagined. One is likely to keep nanos stocked at fairly light levels, which makes it not very difficult to keep sweeper producing species away from other corals. The small size of the corals in question also help here.

Also, not to get anyone’s hopes up, but it -may- be possible to keep goniopora in a Nano with better success then in a traditional tank. The reasons I say this are that it’s long been theorized goniopora waste away from the lack of some essential but unknown trace element. The regular partials involved in Nano keeping may completely eliminate this problem, particularly if natural salt water is used.

[13.2] Soft Corals

Virtually every soft coral tried has been successful. These include:

* White Pulsing Xenia.

* Devils Hand.

* Encrusting Gorgonians

*Colt Coral - mine is growing so quickly I can't keep up with it.

[13.3] Mushroom Anemones (Actinodiscus), Ricordia, Rhodactis

These seem to do well without exception.

[13.4] Encrusting Anemones (polyps)

Zoanthus. No problems. Reproduce well.

[13.5] Tridacna Clams.

Tridacna crocea and Tridacna maxima are both pretty good choices for a nano. Both will grow too large for the tank eventually, however, so realize this before you buy them. If you want to keep one of these clams, make sure you have adequete lighting (I personally wouldn’t try it with less then 45-50 watts of light on ANY size tank) and be prepared to make regular calcium additions.

[13.6] Desireable macroalgae.

Caluerpa seems to do very well, but it's rapid growth rate can cause encroachment problems. I found myself pruning so often that I ended up removing it all from the tank, but many people find the same problems inlarger tanks, so this is no surprise. Halimedia does just fine, and is a much better choice because it has a slower growth rate and is not prone to “crashing” like caulerpa.

Be aware that if Caulerpa goes into sexual mode and crashes in a nano, you'll know it. Your tank water will go almost opaque. I've had this happen to me, but without negative results -- although I did perform a 50% water change as soon as I noticed.

[13.7] Fish.

I personally don't recommend any fish in tanks smaller then 5 gallons, if not 10 gallons. Good choices include various clownfish, gobies, blennies, damsels and pseudochromis, although care must be taken to insure that an individual species is not one which will outgrow the tank.

Do not get a mandarin for a Nano! No one seems to listen when I say this, but in a Nano tank there simply will NOT be enough copepods for the fish’ long-term survival. It will just slowly starve to death, decimating your tank’s population of copepods and amphipods in the process.

[13.8] Herbivores.

Astrea snails are theperfect size, but not as efficient as one might wish. Turbos do a much better job of keeping a tank algae free then astreas, but due to their size they can knock things over easily in a nano. A little underwater epoxy may prevent this from happening. Amphipods thrive and multiply in most nanos.

[13.9] Detrivores.

I'm not sure of the wisdom of using serpent/brittle stars in a Nano. Experience shows that many are predators of opportunity; they may go after fish or other inverts if given the chance, and in a small tank it can be impossible for an animal to escape . As mentioned above, hermits do well and should be considered indispensible. Do not use cucumbers -- these animals give off very toxic substances when distressed or dying. In a tank the size of a nano, these toxins can kill all the inhabitants in an eyeblink.

[14] Costs.

Here is what a 2.5g nano would cost if you purchase all the supplies at full retail (your mileage may vary).

* 2.5g tank $10.00

* glass cover. $ 2.00

* 3 lbs. live sand $ 7.50

* 2 lbs Marshall Rock $20.00

* 15w heater $15.00

* stick-on thermometer $ 2.50

* cheap air pump $10.00

* air valve + tubing $ 4.00

* 2-bulb (18w) MiniMight (Coralife) Flourescent

hood/ballast with 1x9w daylight + 1x9w actinic$70.00

Total $141.00+tax

For a five gallon nano, you should add another few lbs of live rock, plus at least another 3 lbs of live sand, plus and extra couple bucks for the larger tank. Even setting up a deluxe 10 or 15 gallon tank with stand, good venturi protein skimmer and metal halide lighting will only cost around $500 or so, if you shop around enough.

[15.0] Changes planned for the next revision

Next time out I hope principally to be able to offer some information about algal turf scrubbers and mangrove seedlings in a Nano. I'd also like to expand the livestock section significantly.